Metal cover for portable electronic device

ABSTRACT

A casing for a portable electronic device, comprising at least a first and a second cover member and a frame unit. The first and second cover member may be attached to the frame unit and the second cover member may enclose a part of the frame unit, wherein the casing enclose the portable electronic device and is self supporting when the first and second cover member and the frame unit are assembled.

TECHNICAL FIELD

The present invention relates generally to the field of casings or covers for portable electronic devices and, more particularly, to metal casings or covers for mobile terminals.

BACKGROUND ART

The first commercially attractive mobile phones or terminals were introduced in the market at the end of the 1980's. Since then, a lot of effort has been made in making smaller terminals, with much help from miniaturization of electronic components. Today, numerous manufacturers offer pocket-sized terminals with a wide variety of capabilities and services.

In order to attract customers the terminal manufactures have therefore taken further measures to strengthen their position in the competition, one such being to offer terminals with attractive covers.

Most mobile phone covers are made of plastic material, since they are easy and cheap to manufacture. In addition, a plastic cover is insufficiently hard and is vulnerable to cracking in collisions. Plastic covers are usually made by injection molding, which often creates defects during manufacture. Since the thickness of the phones is decreasing, the rigidness of the structure has to be improved.

Covers made of metal have superior hardness and duration, as well as better yield during manufacturing. Metal parts have mainly been used in the covers for cosmetic reasons. Mechanically many of these covers have not added much to the structure of mobile terminals. The metal cover parts are often combined with a plastic cover. There are also difficulties with the fittings and the fixation of the different parts. There are also limitations in manufacture covers of metal. Currently, most metal covers are made by the manufacturing technique known as progressive stamping. A metal plate is pressed into a desired 3-plane shape in several steps. Usually, shapes with sharp edges are nor possible. In progressive stamping the metal plate is extended and thinned. Therefore, the edges will be vulnerable and may fracture easily.

SUMMARY OF THE INVENTION

With the above and following description in mind, then, an aspect of the present invention is to provide a casing for a mobile phone or terminal consisting of a sheet metal casing which seeks to mitigate, alleviate, or eliminate one or more of the above-identified deficiencies in the art and disadvantages singly or in any combination.

An aspect of the present invention relates to a casing for a portable electronic device, comprising at least a first and a second cover member and a frame unit. The first and second cover member may be adapted to being attached to the frame unit and the second cover member may further be adapted to enclose a part of the frame unit, wherein the casing may be adapted to enclose the portable electronic device and to be self supporting when the first and second cover member and the frame unit are assembled.

In one embodiment, the portable electronic device may comprise at least two face portions, two long side portions and two short side portions and the first and second cover members may be adapted to cover the face portions and part of the two long side portions and the frame unit may be adapted to cover the long and short side portions.

In one embodiment, the cover members may be U-shaped and may comprise one face portion and two side portions, wherein the side portions of the first cover member may be attached to the frame unit and the side portions of the second cover member may be adapted to embrace and attach onto the frame unit.

In one embodiment, the second cover member may be adapted to embrace said frame unit completely.

In one embodiment, the second cover member may be supported by the frame unit. Further on, the upper edge of the frame unit may be abutting against the second cover member for supporting the cover member.

In one embodiment, the first cover member may be insert molded onto the frame unit.

In one embodiment, the second cover member may be attached onto the frame unit by a snapping mechanism.

In one embodiment, the frame unit may comprise means for guiding the second cover member when embracing the frame unit. The means for guiding may be at least one projection attached on the outside part of the frame unit. Further on, the projection may be wedge-shaped.

In one embodiment, part of electronics of the portable electronic device may be attached to the frame unit. Further on, part of electronics of the portable electronic device may be attached to the first cover member. Part of electronics of the portable electronic device may also be attached to the second cover member.

In one embodiment, the casing may be manufactured by 2D forming a sheet metal blank.

In one embodiment, the cover members may be manufactured by metal sheet steel.

In one embodiment, the cover members may be manufactured by cold rolled stainless sheet steel.

In one embodiment, the frame unit may be manufactured by plastic.

In one embodiment, the keys may be integrated in one of the first and second cover members. Further on, the keys may be integrated in one of the first and second cover member by reducing sheet thickness in a key area of one of the first and second cover members.

In one embodiment, the first cover member may be the back cover of the casing and the second cover member may be the front cover of the casing.

In one embodiment, the first cover member may be the front cover of the casing and the second cover member may be the back cover of the casing.

Another aspect of the present invention relates to a portable terminal comprising a terminal core, the terminal further comprising a casing described above for covering the terminal core.

The features of the above-mentioned embodiments can be combined in any combinations.

Some embodiments of the invention provide improved structure rigidness of the mobile terminal. It is an advantage with some embodiments of the invention that they may allow for an improved transfer of heat generated in the mobile terminal. It is another advantage with some embodiments of the invention that they may allow for improved fixation of the different parts.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects, features and advantages of the present invention will appear from the following detailed description of some embodiments of the invention, wherein some embodiments of the invention will be described in more detail with reference to the accompanying drawings, in which:

FIG. 1 illustrates a mobile terminal;

FIG. 2 is a cross-sectional view of the short side of a cover member according to an embodiment of the present invention;

FIG. 3 illustrates a mobile phone with U-shaped sheet metal cover members and a battery lid according to an embodiment of the present invention;

FIG. 4 shows the frame unit according to an embodiment of the present invention;

FIG. 5 is a cross-sectional view of one of the cover parts according to an embodiment of the present invention;

FIG. 6 is a side view of the cover part of FIG. 5;

FIG. 7 a, b show further embodiments of the present invention.

DETAILED DESCRIPTION

Embodiments of the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to persons skilled in the art.

The present disclosure relates to the field of portable electronic devices. A preferred embodiment of the invention relates to a portable communication terminal or phone. In a best mode of the invention known to date, the invention can be implemented in a mobile phone. However, although the invention is particularly suitable for mobile phones, it is as such equally applicable to portable electronic devices which do not include radio communication capabilities. However, for the sake of clarity and simplicity, the embodiments outlined herein are related to a mobile phone.

A mobile phone 1 is shown in FIG. 1. The mobile phone 1 comprises a casing 10 arranged to support other elements of the mobile phone. The mobile phone 1 includes a keypad or keyboard 11 and a display 12. Typically, the mobile phone 1 also includes a microphone 13 and a speaker 14. The mobile phone also comprises radio transceiver circuitry, antenna 15. The specific function and design of the mobile phone 1 as a communication device is known to persons skilled in the art, and will therefore not be described in any greater detail herein. It should also be noted that the list of features and elements included in the mobile phone 1 is in no way exhaustive. On the contrary, while the mobile phone 1 shown and described represents only one possible embodiment, it may well comprise further features and elements providing other functions. Also, it should be appreciated that some of the elements listed above are not of importance for the invention as such and can be dispensed with in other embodiments.

FIG. 2-6 illustrates a mobile phone casing according to an embodiment of the invention. The mobile phone includes a first and second opposing face, a first and second opposing shorter side and first and second opposing longer side. As shown in FIG. 2, the casing includes at least a front cover 22, a back cover 21 and a frame unit 23.

The two cover part are adapted to cover any one of the first or second opposing faces and part of the first and second opposing long sides of the mobile phone. The frame is adapted for covering the first and second opposing short sides, the corners and the first and second opposing long sides.

In one embodiment, the back cover 21 is insert-molded with the frame unit at the long side of the mobile phone.

In one embodiment, the casing is assembled by letting the front cover 22 enclose the frame unit 23 at the long side of the electronic device and being attached to the frame unit 23 at the lower part 25 of the frame unit by a snapping mechanism. The cavity between the front cover 22, the frame unit 23 and the back cover 21 then accommodate the electronic parts, the terminal core, of the mobile phone. The frame unit 23, molded to the back cover 22, is then supporting the front cover 22 at several support points 24. At assembly wedge shape protrusions or projections 26 is leading the front cover 22 outwards to make it snap into right position for getting a gap free joint. When all parts are assembled they provide a self-supporting casing enclosing all parts of the mobile phone.

In one embodiment, all the electronic parts of the mobile phone is attached or mounted onto the frame unit 23. In another embodiment may all or some of the electronic parts be attached or mounted onto the frame unit and the other parts may be mounted onto one or both of the cover parts 21, 22.

A disassembling tool 28, including a support 29, may be used to grip front cover 22 at the end part 27, forcing it outwards in X-direction and upwards in the Z-direction. Thus the cover parts are disassembled and it is then possible to reach the terminal core parts of the mobile phone.

The cover parts 21, 22 may be U-shaped and manufactured by a rigid metal sheet blank, such as a thin cold rolled sheet metal. Other material may also be used, such as hard rolled aluminum, magnesium, titanium and bi-metal sheet with one cosmetic surface metal and another metal as support. Polymers as glass or carbon fiber reinforced plastic may also be used.

The frame unit 23 may be manufactured by plastic or another material with appropriate rigidness.

Another embodiment is shown in FIG. 3, which shows a slim mobile phone with U-shaped sheet metal front and back cover and with regular features. At the front cover the keys or the keyboard may be integrated in the cover. This may be done by reducing sheet thickness in the key board area 11 by locally grinding or etching the covers inner side so there will be enough flexibility in Z direction. Flexible enough for letting the stipulated keys travel way with sufficient responding force. Translucent silicon or TPE mat (thermo plastic elastomeric material) is then glued or molded from the inside at the punched key symbols.

FIG. 4 shows an example of a plastic frame 23 according to the invention, with an insert molded sheet metal back cover 21. The plastic frame forms exterior short sides 42, 43 of the casing. The antenna parts and battery part may be enclosed by the frame material, thus the size of metal sheet material area and frame material area at the back cover are decided by the appropriate needed space for the antenna 44 and battery lid functions.

FIG. 5 shows a cross sectional view illustrating the assembling of a display support structure 53 and a sealing part 51 onto the front cover part 21, taking the needed front cover flexibility for the snapping on function into account. The cut outs 52 at the supporting flange for the window is adapted for minimize the reduction of the front cover flexibility. The sealing part also covers the cut out corners 52, as shown in FIG. 5. The differences in the radius of the cut outs are 0.1 mm and the bended radius is 0.9 mm (for ˜″0.4 mm sheet). The assembled display support structure 53 and the sealing part 51 with the display 12 are shown in FIG. 6.

Further embodiments of the casing are shown in FIG. 7 a and b. The casing may be inverted, that is the plastic frame 73 is inserting molded with the front cover 72, where the front cover sheets high rigidness is used to support an all front covering glass 74 or a cosmetic ceramic front. The back cover 71 is snapped onto the frame 73.

A large area of the cover part is used for flexing the cover part, when assembling the casing, for getting a working snap on mechanism and to decrease permanent deformation. The geometry of the snap grip is calculated dependent on snap grip size, sheet metal flex modulus and max allowed elongation. The dimension on the phone thickness and width may also be accounted for when calculating the dimensions.

By using self-supporting casings of cold rolled stainless sheet steel, close to spring quality, the wall thickness can be thin and still resistant to dents and deformations. There are also high performance aluminum sheet grades possible to anodize. These qualities have significant better mechanical performance than the qualities that have been used for 3D formed covers (progressive stamping). For 2D formed covers it may also be possible to use extruded or protruded profiles as aluminum profiles or even carbon fiber composite.

There is a significant reduction in tooling costs and tooling lead time when using 2D sheet forming instead of 3D sheet forming of a blank. 2D sheet forming may be performed in a simple bending machine. Also roll forming of profiled sheet strips is possible and very economic in large quantities. The surface finish treatment for a 2D formed sheet cover can be done in linear process to a great extent, where for instance manual handling for polishing the corners can be avoided.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” “comprising,” “includes” and/or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The foregoing has described the principles, preferred embodiments and modes of operation of the present invention. However, the invention should be regarded as illustrative rather than restrictive, and not as being limited to the particular embodiments discussed above. The different features of the various embodiments of the invention can be combined in other combinations than those explicitly described. It should therefore be appreciated that variations may be made in those embodiments by those skilled in the art without departing from the scope of the present invention as defined by the following claims. 

1. A casing for a portable electronic device, comprising at least a first and a second cover member and a frame unit, wherein said first and second cover member are adapted to being attached to said frame unit and said second cover member is further adapted to enclose a part of said frame unit, wherein said casing is adapted to enclose said portable electronic device and to be self supporting when said first and second cover member and said frame unit are assembled.
 2. The casing according to claim 1, wherein said portable electronic device comprises at least two face portions, two long side portions and two short side portions and said first and second cover members are adapted to cover said face portions and part of said two long side portions and said frame unit is adapted to cover said long and short side portions.
 3. The casing according to claim 1, wherein said cover members are U-shaped and comprises one face portion and two side portions, wherein said side portions of said first cover member is attached to said frame unit and said side portions of said second cover member is adapted to embrace and attach onto said frame unit.
 4. The casing according to claim 1, wherein said second cover member is adapted to embrace said frame unit completely.
 5. The casing according to claim 1, wherein second cover member is supported by said frame unit.
 6. The casing according to claim 5, wherein the upper edge of said frame unit is abut against said second cover member for supporting said cover member.
 7. The casing according to claim 1, wherein said first cover member is insert molded onto said frame unit.
 8. The casing according to claim 1, wherein said second cover member is attached onto said frame unit by a snapping mechanism.
 9. The casing according to claim 1, wherein said frame unit comprises means for guiding said second cover member when embracing said frame unit.
 10. The casing according to claim 9, wherein said means for guiding is at least one projection attached on the outside part of said frame unit.
 11. The casing according to claim 10, wherein said at least one projection is wedge-shaped.
 12. The casing according to claim 1, wherein part of electronics of said portable electronic device is attached to said frame unit.
 13. The casing according to claim 1, wherein part of electronics of said portable electronic device is attached to said first cover member.
 14. The casing according to claim 1, wherein part of electronics of said portable electronic device is attached to said second cover member.
 15. The casing according to claim 1, wherein said casing is manufactured by 2D forming a sheet metal blank.
 16. The casing according to claim 1, wherein said cover members are manufactured by metal sheet steel.
 17. The casing according to claim 1, wherein said cover members are manufactured by cold rolled stainless sheet steel.
 18. The casing according to claim 1, wherein said frame unit is manufactured by plastic.
 19. The casing according to claim 1, wherein keys are integrated in one of said first and second cover members.
 20. The casing according to claim 11, wherein said keys are integrated in one of said first and second cover members by reducing sheet thickness in a key area of one of said first and second cover members.
 21. The casing according to claim 1, wherein said first cover member is the back cover of said casing and said second cover member is the front cover of said casing.
 22. The casing according to claim 1, wherein said first cover member is the front cover of said casing and said second cover member is the back cover of said casing.
 23. A portable terminal comprising a terminal core, the terminal further comprising a casing according to claim 1 for covering said terminal core. 